First post so go easy on me. I am in the process of building an M4 out of a pre-ban Colt lower and possibly a RRA flat-top upper. I am going to mount an Eo-Tech sight directly to the flat-top rail of the upper. I have decided to go with the A.R.M.S. #40L low profile flip-up rear sight. My delima is choosing a front sight. Will the standard front sight housing be visable when I look through the Eo-Tech? I understand the whole "co-witness" thing, but I would prefer a clear un-obstructed view. If I need a front flip up sight, what do you think of the Yankee Hill Front Flip Sight Tower With Bottom Rail Model #YHM-9835A

Any help would be appreciated.

Ive used the YHM flip up frontsight/gasblock that has no bayolug, rail or sling attachment. It works very well.

On my Bushy/VLTOR lower

I added a LMT M4 upper 14.4 1/7 twist with added Phantom

the upper has the regular Front Sight

BUIS is arms 40

and a EOTECH 551


I would go LMT upper if you can afford it

If not STAG M4 upper are good and come with arms 40




The Front sight dosent get in the way while useing a EOTECH or AIMPOINT

remember BOTH EYES OPEN